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 |  | | | | sanjaya大师好
我想问下在电源环路设计和调试中有没有能把伯德图变成平民化的经验呢
在实际电路设计调试，比如电源的纹波大输出电压不稳定是环路那部分影响的，调试方向是如何
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| | | | | sanjaya资料已上传，有需要的工程师可以下载了
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| | | | | 精通第二版 原书 225页 图片上打叉出是错了吗 不明白呢。 本帖最后由 srxz 于 2016-5-21 11:01 编辑
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| |  | | | | | This is Fig 5-2. It breaks up the power conversion process into time slots. All this says is that during this time slot (switch ON), the current in the switch is (on average) equal to output current. We are not averaging the switch current over the entire cycle, since we are only looking at it in these time slots. It is therefore correct, both the figure and the equation.
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|  | | | | | | 回复： srxz 这是在开关管导通时的电流，而不是整个周期的电流，所以还是对的！
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| | | | | | | | | 谢谢 我看明白 了 下面的有错
不知道有没有网友反应的关于书中印刷错误或者排版错误的集合连接？
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| | | | | | | | | | | srxz:
的确，书中存在排版的一些错误，这个地方是错了。谢谢指出。
我们也在想怎么和作者沟通，出一个勘误的东西。因为这本书(A-Z)接触面蛮广的。
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| | | | | | | | | | | | | 谢谢 ，看帖子都是版主整理的，点赞，希望以后多多给我们分享好的资料哈
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| | | | | | | | | | | This is right I think..it is a bit hard to see, but there is a bracket here: (2+r)^2...sorry for the excessive shading, which is hiding the brackets
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| | | | | | | 可以把具体想寻求帮助的问题写一下，方便与作者联系、进行回复。 
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| | | | | | | | | 我这个刚开始做，没啥头绪哈  ，这个一个很大的工程哈，刚入手，想找个师傅指导一下，怎么做工程  ，特别好奇那些大神是怎么干活的  本帖最后由 清风慕竹 于 2016-5-26 09:32 编辑
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| | | | | | | | | | | 从你开始的功率直接降到了1/3功率。
不错，你说的确是一个系统级的工程，并不是一下子就能完成的，至少里面还包括了算法等。
建议：你们公司应该有类似产品先例，可以查阅下之前所做的项目，这样至少不会没有头绪。
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| | | | | sanjaya先生，我想知道电流模式下和有斜率补偿的PWM传递函数是怎么推导出来的，还有boost和buck-boost的power stage函数是怎么推导出来的，如果推导过程太长不方便推导的话请告知那些资料有它们的推导过程，我很想知道他们是怎么的到的，万分感谢！ |
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| | | | | 怎么选择铁硅铝电感的u值？比如选择26或者60或者其他的值，主要考虑哪些因素？ 例如PFC（CCM)，PCF（DCM），H桥逆变LC滤波器
how to choose magnetic permitivity(u value) of sendust core ? why 26? or 60 ?or other value？ what factors to consider? for example CCM PFC, DCM PFC, H Bridge LC filter.
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| | | | | | | Very good question...give me a few days to answer this properly. Thanks!
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| | | | | How the "power stage transfer function " derived from?
Hi,Dear sanjaya !
There is a formula in the book <<switching power supplies a-z>> ,page 321, chinese edition ,2nd edition(OH,I am sorry! I only have chinese edition),
the formula 12-49.
Will you please tell me is there some books,or papers,or application notes about that how this formula come from?
Thank you !
功率级传递函数的推导。
在《精通开关电源设计》这本书的321页中有一个公式 12-49.作者直接给出这个公式而并没有做推导。请问是否有 关于怎么推导这个公式的书 ，文章 或者文档？
谢谢！
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| | | | | | | 我暂时来回答下：
这是一个简单的buck下的控制对象（不包括反馈的）传函：这里忽略了ESR 和 DCR.
一般'开环（这里指不带反馈的）'BUCK一般由三级构成：
PWM调制器级 这个由P319图12-11给出
功率转换级 传函已由 P321的12-48推导出来
LC后级滤波器级 这是一个典型的2阶系统，图P314的12-8 给出
记住，只有buck的VMC模式下才可以如此方便的导出。
其他详细的可以参考Sanjaya的新书：Intuitive Analog to Digital Control Loops in Switchers
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| | | | | | | | | 谢谢 eric!sanjaya 在书本中直接给出了结果。包括 christophe basso 的书也是仅仅给出结果。我想了解整个功率级的传递函数的推导，包括buck ,boost ,buck-boost这三种拓扑。我没有找到对应的书或者文章。
至于sanjaya 的新书，能否给出目录？这本书主要侧重点是哪方面？论坛是否可以组织这本书的团购？
谢谢！
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| | | | | | | | | | | The derivation for buck in voltage mode control in my books...except for RHP zero, which needs detailed modelling.. For boost and buck-boost transfer function derivation, search for "canonical model" as described by Middlebrook. Maybe Erickson has it in his books. I referred to Middlebrook's original papers. Thanks.
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| | | | | | | | | | | | | 新书：Intuitive Analog to Digital Control Loops in Switchers 有电子档吗
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| | | | | | | | | | | | | The derivation for buck in voltage mode control in my books...except for RHP zero, which needs detailed modelling.. For boost and buck-boost transfer function derivation, search for "canonical model" as described by Middlebrook. Maybe Erickson has it in his books. I referred to Middlebrook's original papers. Thanks.
译：因为右半平面零点建模更为复杂和精细的建模，所以除了右半平面零点的推导外，BUCK 系列电压模式控制下的推导在A-Z中的书都有详述。对于BOOST 以及BUCK-BOOSST的衍生拓扑，可以参见Middlebrook的书中关于 规范化模型。或是Erickson的那本电力电子学。个人建议推荐参考 Middlebrook的原始文章。
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| | | | | | | | | 新书：Intuitive Analog to Digital Control Loops in Switchers 有电子档吗
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| | | | | | | | | | | Intuitive Analog to Digital Control Loops in Switchers 这本书还没有电子档，目前亚马逊有售的仅有英文版。 |
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| | | | | | | Hello, On page 312 I derived the transfer function of the LC filter. This is multipled by the transfer function of the PWM block, i.e. 1/Vramp and also multipled by the transfer function of the switch, which is Vin....so the transfer function of the "plant" is the product of the transfer functions of its constituent blocks. That is the equation you are referring to omn Page 321
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| | | | | | | | | Hello, On page 312 I derived the transfer function of the LC filter. This is multipled by the transfer function of the PWM block, i.e. 1/Vramp and also multipled by the transfer function of the switch, which is Vin....so the transfer function of the "plant" is the product of the transfer functions of its constituent blocks. That is the equation you are referring to omn Page 321
译： A-Z 2版的P312已经推导出来了LC滤波器的传函数，然后它与PWM模块的传递函数相乘，如1/Vramp这样。再与开关级的传递函数相乘，对于Buck而言，即为Vin. 所以整个控制对象的传递函数是三个级联模块相乘。即得到P321的方程。
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| | | | | | | | | | | 那个PWM的传递函数1/Vramp应该是根据电压模式推导出来的，但是电流模式下还有加了斜率补偿的PWM传递函数应该有所不同!但又不知道如何推导，还望赐教！谢谢！
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| | | | | Hello SanjayaMay I ask you a question?
Will PFC support swith load？ In general the PFC voltage loop bandwidth is too narrow,switching load is not recommended. So I would like to ask your opinion.
I am made of three-phase rectifier UCC28070 boost output( 630 v5000w )swiching from 2500W to5000W or 1000 w to 5000 w
Resistive load by air switch
本帖最后由 inocencelove 于 2016-6-17 13:56 编辑
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| | | | | | | Hello inocencelove, the PFC stage has to have a very slow voltage correction loop. It should not react to try and correct the output voltage ripple too quickly, which varies at a rate of 100Hz. The reason is explained in A-Z/2e where I show that the average diode current must be a Sine squared function if the input current waveform is to be a sine waveform. Which means the output cap will necessarily have a voltage ripple, and the PFC stage should accept that --- otherwise the input current waveform cannot be a sine wave! However, the PFC stage is followed by a PWM stage....and if you switch the load on that, that can be a good buffer. Basically, suppose you suddenly increase the load on the PWM stage output, it will draw current suddenly from its input cap, which is the output cap of the PFC stage. Since the PFC stage responds very slowly to a change in voltage on its output cap, the voltage on the cap will droop. But the PWM stage, can in principle provide fast output regulation even if its input sags. But make sure the capacitor is large enough so that the PWM stage can handle the input variation. For example, if it is a standard Forward converter, ensure it does not hit its duty cycle limit of ~50%. And so on. However, if you just apply a switched load directly to the PFC output, certainly the PFC stage cannot correct that...it takes a few AC cycles to respond as mentioned above.
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| | | | | | | | | Thank you for your answer.
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| | | | | 你好,在开关电源里效率 最高的是BUCK结构的电源,那么从哪几个方面进行优化,可以使电源的效率达到最优.
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| | | | | 各位网友有福了，能与《精通开关电源设计》原书作者Sanjaya面对面真是一种缘分。
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返回新版
谢谢小青。。。。辛苦了！
感谢大力兄关注，培训资料都有了 ，可以下载阅读。
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